package/htop: fix LICENSE

see https://github.com/htop-dev/htop/blob/3.1.1/ChangeLog#L3

Signed-off-by: Francois Perrad <francois.perrad@gadz.org>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/htop/htop.mk

@@ -10,7 +10,7 @@ HTOP_DEPENDENCIES = ncurses
 HTOP_AUTORECONF = YES
 # Prevent htop build system from searching the host paths
 HTOP_CONF_ENV = HTOP_NCURSES_CONFIG_SCRIPT=$(STAGING_DIR)/usr/bin/$(NCURSES_CONFIG_SCRIPTS)
-HTOP_LICENSE = GPL-2.0
+HTOP_LICENSE = GPL-2.0+
 HTOP_LICENSE_FILES = COPYING
 
 ifeq ($(BR2_PACKAGE_HWLOC),y)